/**
 * 
 */
package com.hydra.designpattern.observer;

/**
 * 
 * @Created on 2013-4-2
 * @Title:主题/被观察者
 * @Description:
 * @author:黄海军
 */
public interface Subject {
	public void addObserver(Observer o);

	public void deleteObserver(Observer o);

	public void notifyObservers();

	public boolean hasChaged();
}
